The general concept of using an apparatus to facilitate weight training such as disclosed in Mazman, U.S. Pat. No. 3,905,599, and Yatso, U.S. Pat. No. 3,912,263, has been known for a significant amount of time. These types of devices enhance the ability to perform the weight training exercises but also increase the safety of performing the weight training exercises.
Fuhrhop, U.S. Pat. No. 4,286,782, discloses an adjustable exercise device that permits the configuration of different components to be changed to facilitate performing different exercises. The Fuhrhop device includes a series of holes along the posts that permit attachment at different locations on the posts. Similarly, Sterba et al., U.S. Pat. No. 4,700,944, and Rasmussen, U.S. Pat. No. 6,015,369, each disclose a weight training system in which components are connected in different positions to facilitate performing different exercises.
Yakata, U.S. Pat. No. 4,763,897, discloses an exercise device that includes a support platform and a pivot lever. The pivot lever is slidable with respect to the support platform. It is also possible to adjust the initial angular orientation of the pivot lever and a distance between the support platform and an end of the pivot lever opposite the support platform. Rotation of the pivot lever causes a weight stack to be lifted.
Webber, U.S. Pat. No. 5,800,321, describes an exercise apparatus a pivotally mounted linkage mechanism. Pivoting of the linkage mechanism with respect to a support frame adjusts a height of linkage mechanism to facilitate performing a variety of exercises with the exercise apparatus.